/*
 * Copyright (c) 2007, 2015, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */
/*
 * Copyright 2002,2004 The Apache Software Foundation.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.sun.org.apache.xml.internal.serialize;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.InputStream;

import java.security.AccessController;
import java.security.PrivilegedAction;
import java.security.PrivilegedActionException;
import java.security.PrivilegedExceptionAction;

/**
 * This class is duplicated for each subpackage so keep it in sync.
 * It is package private and therefore is not exposed as part of any API.
 *
 * @xerces.internal
 */
final class SecuritySupport {

  private static final SecuritySupport securitySupport = new SecuritySupport();

  /**
   * Return an instance of this class.
   */
  static SecuritySupport getInstance() {
    return securitySupport;
  }

  ClassLoader getContextClassLoader() {
    return (ClassLoader)
        AccessController.doPrivileged(new PrivilegedAction() {
          public Object run() {
            ClassLoader cl = null;
            try {
              cl = Thread.currentThread().getContextClassLoader();
            } catch (SecurityException ex) {
            }
            return cl;
          }
        });
  }

  ClassLoader getSystemClassLoader() {
    return (ClassLoader)
        AccessController.doPrivileged(new PrivilegedAction() {
          public Object run() {
            ClassLoader cl = null;
            try {
              cl = ClassLoader.getSystemClassLoader();
            } catch (SecurityException ex) {
            }
            return cl;
          }
        });
  }

  ClassLoader getParentClassLoader(final ClassLoader cl) {
    return (ClassLoader)
        AccessController.doPrivileged(new PrivilegedAction() {
          public Object run() {
            ClassLoader parent = null;
            try {
              parent = cl.getParent();
            } catch (SecurityException ex) {
            }

            // eliminate loops in case of the boot
            // ClassLoader returning itself as a parent
            return (parent == cl) ? null : parent;
          }
        });
  }

  String getSystemProperty(final String propName) {
    return (String)
        AccessController.doPrivileged(new PrivilegedAction() {
          public Object run() {
            return System.getProperty(propName);
          }
        });
  }

  FileInputStream getFileInputStream(final File file)
      throws FileNotFoundException {
    try {
      return (FileInputStream)
          AccessController.doPrivileged(new PrivilegedExceptionAction() {
            public Object run() throws FileNotFoundException {
              return new FileInputStream(file);
            }
          });
    } catch (PrivilegedActionException e) {
      throw (FileNotFoundException) e.getException();
    }
  }

  InputStream getResourceAsStream(final ClassLoader cl,
      final String name) {
    return (InputStream)
        AccessController.doPrivileged(new PrivilegedAction() {
          public Object run() {
            InputStream ris;
            if (cl == null) {
              ris = ClassLoader.getSystemResourceAsStream(name);
            } else {
              ris = cl.getResourceAsStream(name);
            }
            return ris;
          }
        });
  }

  boolean getFileExists(final File f) {
    return ((Boolean)
        AccessController.doPrivileged(new PrivilegedAction() {
          public Object run() {
            return new Boolean(f.exists());
          }
        })).booleanValue();
  }

  long getLastModified(final File f) {
    return ((Long)
        AccessController.doPrivileged(new PrivilegedAction() {
          public Object run() {
            return new Long(f.lastModified());
          }
        })).longValue();
  }

  private SecuritySupport() {
  }
}
